In the livestock industry, dried pasture in which pasture such as hay and straw harvested from summer to fall is dried, or ensilage in which the dried pasture had been subjected to lactic acid fermentation has heretofore been stored and utilized as a livestock feed in winter. For making hay or straw, etc., as the dried pasture or ensilage, hay or straw, etc., is firstly wound to a roll state by a roll baler machine, and molded to a cylindrical shape to form a roll bale. Next, the roll bale is covered by a wrapping net, etc., so as not to collapse the shape and allowed to stand for several days. Thereafter, the roll bale in a suitably dried state is strictly coated by a wrapping film on the wrapping net, and conveyed and stored.
When the thus stored pasture is used as a feed, the wrapping net and the wrapping film are removed, and the pasture is made a feed in an easily edible state using a stirrer. At this time, the removed wrapping net and wrapping film are disposed as industrial wastes.
Thus, the wrapping net is an optimum material not only for preventing from collapse of a roll bale, but also for drying of a pasture due to its high air permeability. On the other hand, the wrapping film is an optimum material not only for preventing permeation of air or moisture into the pasture, but also for improving strength of the roll bale. The method of wrapping the roll bale utilizing such a wrapping net and a wrapping film has been starting to spread throughout Japan including Hokkaido since it is suitable for conveyance and storage of the pasture.
On the other hand, in recent years, a business utilizing the hay or the straw, etc., not for a dried pasture or an ensilage, but for a fermentation raw material of bioethanol which is a carbon neutral fuel has been started. In addition, not only the hay or straw, plants cur for maintaining a bank of a river are also considered to be utilized as a fermentation raw material of bioethanol. Thus, when the hay or the straw, etc., is utilized as the fermentation raw material, it is effective to wind these in a roll state by a roll baler machine, mold to a cylindrical shaped roll bale and convey and store in a factory to be processed.
Wrapping machines shown in the following mentioned Patent Document 1 or the following mentioned Patent Document 2, etc., are apparatuses for carrying out wrapping of a roll bale by a wrapping film automatically and efficiently. On the other hand, in the wrapping with a wrapping net, these wrapping machines are also used.